14 MALL. [Vor. XIX. 
tion and the other in which there is an atrophic or rudi- 
mentary hand or foot attached. In the latter instance it 
seems to me that it is very irrational to hold the umbilical cord 
responsible for the amputation. Furthermore, the cause is 
possibly germinal, as may be the case in sympodia, syndactyly 
and ectrodactyly. The rare cases in which there is actual 
amputation of the extremity are more likely to have been 
produced by mechanical injuries during labor than by having 
the amputated limb caught in a loop of the umbilical cord. 
In fact, we must admit that we are unable to explain by any 
satisfactory hypothesis either congenital amputations or dis- 
locations. 
It has been noticed occasionally in merosomatous monsters 
that the diseased or malformed part is tied by means of 
bands of tissue either to the amnion or to adjacent parts of 
the body of the fcetus. These observations, relatively few in 
number, have led to the theory that the bands caused the 
deformity. It seems to me that, in view of the idea that 
many monsters are due simply to an arrest of development 
of some part of the embryo, that hydramnios is usually pres- 
ent, and that all kinds of monstrosities may be produced in 
lower animals (including amphibia which have no amnion), 
it is highly probable that amniotic bands and the like are 
secondary in their formation and have nothing whatever to 
do with the production of monsters. The more the embryo- 
logical theory is tested by experimental methods the more 
all simple mechanical explanations suffer, and it seems to me 
that all of them will have to be abandoned. 
It 1s not especially remarkable to find that when the head or 
face is malformed the diseased part occasionally forms a sec- 
ondary attachment with the amnion; or that, as in exomphalos, 
where the umbilical cord is “dilated,” the extruded viscera 
come in direct contact with the placenta, as they should, and 
the blood-vessels are scattered and run along the amnion to the 
placenta, as should also be the case when the subject is 
viewed from the standpoint of embryology. Furthermore, de- 
formities of the extremities are of frequent occurrence, but 
